Machines such as trolley-assist machines or electric locomotives generally employ a pantograph assembly to provide electrical power to the machine. Typically, the pantograph assembly is carried on a top surface of the machine. The pantograph assembly is configured to draw power from an overhead conductor and transfer it to the machine. Typically, the pantograph assembly includes a carbon brush and an end horn associated with the carbon brush. During normal operation, the overhead conductor is in contact with the conducting carbon brush. However, in case the machine may have a lateral movement, due to a transition of the overhead conductor between the conducting carbon brush and the non-conducting end horn arcing may occur. This results in pitting and damage to the carbon brush.
Japanese Patent Number JP 55128104 (104 patent) discloses a pantograph having a horn formed by bending a pipe made of a light alloy into a shape of a circle with a suitable radius. The section of the horn is circular at a first joint with a bow part, and is ellipsoidal at a second joint. On the surface of the horn, resistance wires are wound in a combination or resistors are fixed thereby to form a sliding resistor to detect a position of a contact point with an overhead conductor. However, the '104 patent does not address the situation where arcing may occur between the overhead conductor and the carbon brush.